Alternative Digitization Approach for Stereo Phonograph Records Using Optical Audio Reconstruction

This paper presents the first Optical Audio Reconstruction (OAR) approach for the long-term digital preservation of stereo phonograph records. OAR uses precision metrology and digital image processing to obtain and convert groove contour data into digital audio for access and preservation. This contactless and imaging-based approach has considerable advantages over the traditional mechanical methods, such as being the only optical method with the potential to restore broken stereo records. Although past efforts on monophonic phonograph records have been successful, no attempts on 33rpm long-playing stereo records (LPs) have been reported. By using a white-light interferometry optical profiler, we are able to extract stereo audio information encoded in the 3D profile of the phonograph record grooves.